Throughout this specification, the term "video clip" will denote one or more consecutive frames of video data, the term "still image clip" will denote data representing one or more identical frames of still image data (or text), and the term "audio clip" will denote audio soundtrack data corresponding to one or more video clips. A video clip (or a still image clip) can be a scene of an edited video program.
Throughout this specification, the expression "display of a clip" and denotes display (at a single time) of a representation of the data defining the clip, unless qualified to read "sequential display of a clip". Similarly, "displayed clip" denotes a simultaneously displayed representation of the data defining the clip, unless qualified to read "sequentially displayed clip". The expressions "sequential display" of a program, "sequential display" of a clip, and variations on these expressions, denote the non-simultaneous (time-sequential) display of a sequence of representations of data sets, where the data sets collectively define a program or clip.
Throughout this specification, including in the claims, the expressions "edited video program," "video program," and "program" are used interchangeably to denote a sequence of video clips or still image clips (or video clips and still image clips), a transition between each pair of consecutive video and/or still image clips, and optionally also a sequence of audio clips. Each of the transitions between video (and/or still image) clips can be a simple "cut," in which the last frame of a first clip is concatenated with the first frame of a second clip. Alternatively, one or more of the transitions can be a more complicated (special effect) transition, such as a wipe, fade, or dissolve. For example, an edited program can consist of a first video clip, followed by a simple cut to a second video clip, followed by a dissolve transition to a third video clip.
Typically, an edited video program consists of a sequence of video and still image clips (with special effect transitions between consecutive pairs of these clips), and two or more sequences of audio clips (for example, two sequences of audio clips representing left and right channels of an audio soundtrack).
It is conventional to define an edited video program by employing a programmed computer to perform video editing operations in which the computer processes stored digital data representing segments of the video program. A conventional system of this type is disclosed in U.S. Pat. No. 4,538,188, issued Aug. 27, 1990, to Barker, et al. The system of U.S. Pat. No. 4,538,188 employs a computer to control the display and manipulation of pictorial labels (or label pairs), each representing an unedited video segment (or transition between consecutive video segments), in order to assemble an edited video program from unedited video segments. The system also assembles (from the unedited video segments) and displays a sequence of the pictorial labels, which represent scenes (and transitions between scenes) of the edited program. The video segments are stored on video tape, as is the assembled video program. The system has controls which enable a user to specify a variety of transitions between consecutive video segments.
Other video editing systems have been proposed which include means for storing unedited video clips (on video tape or laser video disks), and computer means for controlling the display of selected unedited video clips (or frames of video clips) and generating an edit list in response to user-entered commands.
For example, U.S. Pat. 4,746,994 (issued May 24, 1988, to Ettlinger) discloses a computer-based video editing system in which unedited clips are stored on video tape recorders or video disk players. A computer system enables the user to control the video tape recorders and generate an edit list. The computer system displays a sequence of menus which prompt the user to perform various editing operations (such as displaying desired frames of the unedited clips, shuttling frame-by-frame through a stored unedited clip, adding edits to an edit list, and playing back the sequence of clips defined by the edit list). The user may select various ones of the editing operations by actuating a light pen.
For another example, U.S. Pat. 4,754,342 (issued Jun. 28, 1988, to Duffy) discloses a computer-based video editing system in which unedited clips are stored on video disk players. After generating an edit list, the user may command the system to splice clips in accordance with the edit list and play back an edited show. By using a control console with control buttons and a control dial, the user may command the system to display individual frames of the stored clips, or "roll" one or more clips (or an edited sequence of clips) in forward or reverse motion, at any of a variety of speeds.